Many biomedical procedures require the provision of healthy tissue to counteract the disease process or trauma being treated. This work is often hampered by the tremendous shortage of tissues available for transplantation and/or grafting. Tissue engineering may ultimately provide alternatives to whole organ or tissue transplantation. In order to generate engineered tissues, various combinations of biomaterials and living cells are currently being investigated. Although attention is often focused on the cellular aspects of the engineering process, the design characteristics of the biomaterials also constitute a major challenge in this field.
In recent years, the ability to regenerate tissues and to control the properties of the regenerated tissue have been investigated by trying to specifically tune the mechanical or chemical properties of the biomaterial scaffold (Kim et al., 1997; Kohn et al. 1997). The majority of work has involved the incorporation of chemical factors into the material during processing, or the tuning of mechanical properties by altering the constituents of the material.
The foregoing methods have been used in an attempt to utilize chemical or mechanical signaling to affect changes in the proliferation and/or differentiation of cells during tissue regeneration. Despite such efforts there remains in the art a need for improved biomaterials, including composite materials, particularly those with a better capacity to support complex tissue growth in vitro (in cell culture) and in vivo (upon implantation).